New Delhi: Five government websites, including one of DRDO dealing with recruitment of scientists in the premier defence research organisation, were recently attacked by Algerian hackers and had to be blocked temporarily as a precautionary measure.

The websites have been restored by cyber security sleuths, a top official said today.

"Five sites were hacked on the night of October 29 by Algerian hackers. We have restored the websites. Vulnerabilities have been found and we are strengthening these websites," Indian Computer Emergency Response Team (ICERT) Director General Gulshan Rai said.

The other sites that were hacked were Recruitment and Assessment Centre (RAC), Rehabilitation Council of India, Directorate of Estates and that of Sam Pitroda, Advisor to the Prime Minister on Public Information, Infrastructure and Innovations.

All these sites were managed by the National Informatics Centre (NIC).

There was no threat of loss of sensitive information relating to the Defence Research and Development Organisation since the website did not contain this matter, DRDO said.

DRDO`s Recruitment and Assessment Centre (RAC) has a website rac.gov.in hosted by the National Informatics Centre (NIC) for disseminating career-related information in the organisation.

"On 30 October 2012, suspicious activity was noticed on the NIC server hosting the website. The NIC, as a precautionary measure, therefore temporarily blocked access to the server hosting the RAC website and restored it next day," DRDO said in a release today.

It said the website was fully functional and the main public website of DRDO has not been affected in any manner.

"As such, the website does not contain any sensitive information related to the DRDO," it said.

In recent times, Indian government websites have come under attacks from foreign hacking groups and the National Security Council (NSC) has taken several measures to tackle the menace.

During the Commonwealth Games itself, 8,000 cyber attacks were launched on the ticketing and other important systems functioning there.